Field Study VI: The Effect of Loading Strategies on Removal Efficiencies of a Hybrid Constructed Wetland Treating Mixed Domestic and Agro-Industrial Wastewaters

Abstract

The treatment of domestic wastewater using constructed wetlands (CWs) is common in the Czech Republic; however, the treatment of agro-industrial wastewater is still at the beginning of its application. A hybrid CW consisting of two horizontal filters (HF1 and HF2), one vertical filter (VF), and three stabilization ponds (SP1–SP3) was put into operation in 2012 in Chramce, Usti region, Czech Republic. The hybrid system treats mixed household and agro-industrial wastewater mainly from sheep farms and wine and fruit juice production factories. The filters are planted with Phragmites australis, Phalaris arundinacea, Iris pseudacorus, Iris sibirica, Glyceria maxima, and Lythrum salicaria. In a fed-batch operation, the inflow values vary on the basis of wine processing seasons. In high season, it reaches 17,012 mg L−1 of chemical oxygen demand (COD), 1806 mg L−1 of biochemical oxygen demand (BOD5), and 43,723 mg L−1 of total suspended solids (TSS) on average. Despite such high inlet concentrations, the removal efficiency (RE) for the three selected parameters reached up to 99% for all the parameters. In this work, the removal of four pharmaceuticals (diclofenac, ibuprofen, ketoprofen, and naproxen) in the hybrid system was studied as well. The CW performed high RE for all of the four pharmaceuticals when the RE of diclofenac, ibuprofen, ketoprofen, and naproxen was 81.1%, 93.2%, 96.7%, and 78.3%, respectively.